staging: iio: Remove parantheses around right hand side of assignment

Remove parantheses on the right hand side of assignments as they are not
needed. Coccinelle patch used:
@@
expression a, b, c, d;
@@

(
  a = (c == d)
|
  a =
- (
  b
- )
)

Signed-off-by: Janani Ravichandran <janani.rvchndrn@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>